相关实验视频
Updated: Jul 13, 2026
14:40
Expression Analysis of Mammalian Linker-histone Subtypes
Published on: March 19, 2012
概括
从染色质中去除基因组H1将其结构从紧密包装的纤维转变为"串上的珠子"的形成. 通过电子显微镜观察到的这种结构变化突出显示了histon H1的存在.
科学领域:
- 分子生物学分子生物学
- 染色体结构 染色体结构
- 基因组蛋白质 基因组蛋白质
背景情况:
- 染色体是DNA和蛋白质的复合体,形成基因组组织必不可少的纤维.
- 基因组是染色质结构中的关键蛋白质,其中基因组H1起着重要作用.
- 了解染色体纤维动态对于基因调节和DNA过程至关重要.
研究的目的:
- 为了研究基因素H1去除对染色体纤维的结构影响.
- 用电子显微镜来描述色素的形态变化.
- 阐明 histone H1 在维持色素纤维组织中的作用.
主要方法:
- 使用AG 50 W - X2树脂的离子交换染色学从染色质中选择性去除histon H1.
- 在酸盐缓冲器中使用不同度的NaCl (50-100mM和≥650mM) 进行处理.
- 通过电子显微镜分析色素结构,观察纤维形态和核细胞间距.
主要成果:
- 染色体与所有基因组都表现出密集的核细胞在250个A纤维中.
- 选择性去除 histone H1 导致具有分离核体 (150-200 A 间隔) 的"串珠"外观.
- 高度盐 (≥650 mM NaCl) 破坏了染色质组织,导致不规则的纤维.
结论:
- 基斯H1对于染色体纤维的紧,高阶结构至关重要.
- "串上的珠子"模型准确地描述了基因组H1耗尽后的染色质结构.
- 删除H1基因组显著改变染色体纤维形态,影响其更高阶组织.
相关概念视频
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...